Biomass in a Tube

Biomass will play an increasing role in filling the world's demand for energy and chemicals. Producing enough biomass will take land and lots of it. As Will Rogers said when advising people to buy land, "They ain't making more of the stuff." Harvesting more biomass per acre for food and fuel to feed and run a growing world population is the key, and microscopic algae may be a major player.

By Jerry W. Kram

Growing acres of algae in tubes requires more than scientific and engineering expertise. It takes a lot of sunlight. That's why Glen Kertz, a plant physiologist, is conducting his research in El Paso, Texas, where there are 340 days of sunshine a year.

Sunshine is the fuel for an algae propagation system that Kertz calls Vertigro. On the outskirts of El Paso, Texas, Kertz's company Valcent Products Inc. and its operating partner Global Green Solutions are developing Vertigro as a joint venture. In September, Biomass Magazine attended a briefing on the algae project for media and investors. Inside the company's compound, a greenhouse shelters a series of racks, each of which supports a sheet of a proprietary plastic formed into a set of tubing. With the gentle hum of pumps in the background, streams of green-tinted water flows through the huge plastic bags to be collected for transport back to a holding tank.

"What I am doing out here I consider to be an agricultural crop and an agricultural project," Kertz said. "Everything we do out here is about sustainable, renewable, intensive agriculture." The emphasis on intensive is deliberate. His goal is to create a system that will pull carbon dioxide from the air while creating valuable products to make fuel, pharmaceuticals and other products.

Kertz, who has worked with algae for more than 20 years, started thinking about using it as a biomass feedstock after hearing about a project using plants that fertilize oceans with iron to create huge algae blooms that pull carbon dioxide from the air. "Being a bit of an ocean buff, I went ‘We don't want algae blooms like this because they will kill everything in the vicinity,'" he said. "They would create giant dead zones in the ocean. The last thing we need in the ocean right now is giant dead zones." Kertz went to the investor group looking at the ocean fertilization project and told them there were better ways to sequester carbon dioxide. "I told them algae are the most efficient organisms in the world for converting carbon dioxide into biomass and releasing oxygen. That got their attention and then I said, ‘Oh and by the way, as a byproduct you get 50 percent of the weight as a lipid." They asked what a lipid was and when I said ‘oil,' all hell broke loose."

That was about 1½ years ago when the biodiesel industry was prominent in the news. Six months later, Valcent teamed with Global Green Solutions and broke ground on the Vertigro test facility in El Paso. Global Green became the operating and engineering partner while Kertz and Valcent were the research and development team. "Global Green Solutions is another small, publicly traded company that has the expertise to build out [the Vertigro system] large scale," Kertz said.

Sophisticated ResourcesKertz founded Valcent about three years ago and soon took the company public. The company successfully launched a skin care product called the Nova System. That success attracted investors and in turn allowed Kertz to pursue a dream of his: large-scale algae production. "[The investors] got behind me when I told them what I wanted to do out here," he said, gesturing toward the greenhouse. "We've been very well funded to do this project, obviously."

Kertz was able to build his pilot project with a fully equipped, advanced microbiological laboratory. Inside the ordinary-looking steel building is equipment that wouldn't be out of place at a leading research university, said Kertz pointing to the granite-topped microscopy table, which has steel legs that are driven six feet into the earth to prevent vibrations. Stability is important for the micromanipulators that can pull a single cell off a slide for isolation and culturing. There is also a robotic culture chamber that can test strains of algae in hundreds of different environments in a matter of days to design the optimum conditions for biomass or lipid production.

Kertz went out and found the best people he could to create and carry out his vision. "For any growing company the top thing is to find a good crew," he said. "I've been blessed with a tremendous crew here. We've recruited locally and had people come in like Aga Pinowska. She's one of the pre-eminent algae experts on the planet. If you look around, this was a patch of weeds 11 months ago. Most people look at this and say, ‘you can't do this in 11 months.' But we did it. We did it with a crew that just doesn't stop. We work nights, weekends, the whole works."

The Vertigro system uses specially designed plastic bags as photobioreactors. The bags hang on racks where water containing the algae is pumped in. The water flows back and forth, allowing for ample mixing so the algae get plenty of light. At the bottom, a collection pipe carries the water to a holding tank. The holding tank is important, Kertz said, because the algae grow best when they can spend some time in the dark. Sensors monitor pH and nutrients as well as the density of the culture. One of the reasons the system works so well is its use of sophisticated sensors and probes for monitoring, Kertz said. "They weren't even available five years ago."

While the concept is simple, the devil is in the details. The company has worked with plastic manufacturers to come up with a material that would last five years in the Texas sun without becoming brittle. The goal is to find a plastic that will last 10 years or more. In the microbiology lab, hundreds of varieties of algae were tested for their usefulness for energy or bioproduct production, and the precise blend of nutrients needed for maximum production. "Growing a flask of algae in a laboratory is one thing, growing an acre of algae in photobioreactors in a closed-loop system is a whole different animal," Kertz said. "Understanding flow rates, a dynamic system, growing something in a large closed loop, those are things I have experience in."

When there are enough cells, the water can be filtered and the algae are collected as a thick paste. Under ideal conditions, the algae can double its numbers in 24 hours. That means if half the algae in the system are harvested, by the next day it will be ready to harvest again, Kertz said. "As we pull it off it is growing back," he explained. "So it's a continuous process. If we want to get to the point where we're meeting the demand on the feedstock side of things, we have to have continuous production. It's just critical to the system."

The algae are separated from the water with a centrifuge. Oil can be extracted from the algae in much the same way as from oilseeds, by cold pressing or solvent extraction. The pilot system will be using supercritical carbon dioxide extraction to extract nearly 100 percent of the oil without using potentially hazardous chemicals such as hexane, Kertz said.

Fast TrackKertz wants to see his system developed on a fast track. The plan is for the demonstration plot to prove itself out over the next few months and then to build a full-scale or one-acre pilot plant in the summer of 2008. Small-scale and pilot plants for customers would come later in the year. Using a modular approach, a producer would add one-acre units, each capable of producing 100,000 gallons of algae oil a year, until reaching the desired production capacity. Each unit will contain 20,000 of the photobioreactor bags. "When you go from a fraction of an acre to an acre and then to 100 acres, there are some design challenges," Kertz said. "But the basic engineering is complete. We don't see anything that says the technology is going to be a barrier to us. Expanding is not an issue. Building the reactors and hanging them is not an issue. It's just the physical nature of building up to that size. It's just basic engineering."

Kertz thinks the system's modular design will be a selling point to companies hungry for feedstock. As soon as one unit is completed it will be able to be put into production while other units are being built. "It allows us to do a couple of things. If a customer comes to us and wants to get to 100 acres, but they need the feedstock today, they can start with an acre," he said. "Once that unit is completed in 30 or 40 days, it's producing feedstock. Then we can go to the second acre, the third acre and the fourth. And since they are modular, if this acre for some reason has a failure of some type-and I don't know of any system that won't eventually have a crash-I can isolate that crash from the system and still provide the feedstock on a regular basis."

Many companies are pursuing research into algae production. Kertz believes his background and crew give Vertigro a distinct advantage. "A lot of that has to do with different approaches. A lot of the companies [working with algae] come from the energy sector. A lot of them are very qualified engineers, but they aren't plant physiologists, they're not algae experts. Their approach is a little different from ours. While it is about the end product, we approach it from the point of what do these organisms need."

Information the company presented at the briefing in September showed a tentative price for algae oil of $1.70 a gallon, compared with $2.63 for soybean oil, but Kertz hedged on those numbers. "I am very confident at this point that we can produce feedstock at a cost competitive to fossil fuels. I'm not going to put a dollar figure on it, but I will say we will be very cost competitive. Whether we're making five barrels an acre or 5,000 barrels an acre, as long as we're competitive, we're in the marketplace, and that is the name of the game."

The Vertigro team's work has attracted the attention of the biodiesel industry, although at this point in the process Kertz couldn't provide any names. "We've been approached by some of the larger companies in the world," he said. "Some have actually been out here [to the test facility]. Some are actually in negotiations with us and we hope to see the fruits of those efforts in the next few months."

Whether the Vertigro system is the answer or not, an alternative is inevitable, Kertz said. "The writing is on the wall about what has to happen," he said. "From my perspective, we have to get away from using food stocks as an energy source. We can't drive our cars on corn or soybeans. We can't use that land for energy production. We have to find some way of using nonarable land to produce energy. Whether that is wind power or solar, we have to move that further up the chain. And obviously from my perspective I think algae are one of the answers."

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